[devel] Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES

and updated the "last change" comments to 1.5.0
diff --git a/pngpread.c b/pngpread.c
index 0fe061f..f809901 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.4.1 [February 9, 2010]
+ * Last changed in libpng 1.5.0 [February 9, 2010]
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * and license in png.h
  */
 
-#define PNG_INTERNAL
+#define PNG_EXPOSE_INTERNAL_STRUCTURES
 #define PNG_NO_PEDANTIC_WARNINGS
 #include "png.h"
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED